Means for surveying bore-holes.



PATENTED JAN. 1

HL P. MARRIOTT. MEANS PoR SURVEYING BoRE HOLES.

APPLICATION FILED FEB.21, 1905.

UNITED STATES PATENT OFFICE. HUGH FREDERICK MARRIOTT, oF PARKTOWN,TRANsvAAL.

M EANS FOR SUHVEYING ABOREfHOLES-l Ne. 840,14s.

A Specification of Letters Patent.

Patented Jan. l1, 1907.

Original application filed ingust 30, 1904, Serial No".` 222,776.Divided and this application tiled February 21, 1905. lSerial To allwhom it ma/ycocern; i

vreference to means ordevices for surveying bore-holes, and moreespeclally to an Instrument or device for determining the amount of dip.i g

In a prior application for patent filed by me on the 30th of August,1904, lunder Serial No. 222,776, I describe an instrument desi ned forthe purpose above s eciiied in W -ch electricity is employed an by meansof which a complete and continuous reading is obtained as the instrumentis lowered down the bore-hole, which reading may/be verified as theinstrument is withdrawn from the bore-hole. I

The present invention, which is a division of the above-mentionedapplication, has particular reference to an instrument of this kind, andit relates especially to the means lfor transmitting the movements. ofthe switch-arm over the commutator.

In ythe arrangement described and illustrated in my prior application,Serial No.V 222,776, the electrical connections aresuch that theswitch-arm irst makes a free current, then a blank, then a resistance,then a blank, then a free current, then a blank, then a resistance, andso on.

, According to the present invention the electrical connectionsare soarranged that the switch-arm starts from a normal osition with a maximumresistance and gra ually as the switch-arm moves over the commutatorcuts out the resistance, each segment of the resistance beinginterspacedwith a blank.

In order that the application' of mypresent improvement may be morereadily understood, I append an ex lanator'yr sheet of drawings, whichis marke with characters of reference corresponding to the followingdescription.

In the drawin s, Figure 1 represents a vertical sectional e evationofthat portion of the instrument to which my present improvements areapplied, and Flg. 2 is a diagrammatical representation of the electricalconnections embodying the improvements. Fig. 3 is a detail. f

The instrument is illustrated in Fig. 1 constructed in accordance withmy prior application, Serial No. 222 ,77 -'that is to say, it co'nsistsof a tube 1, which serves to inclose the several `operative parts of theinstrument. Inside this tube is pivotally supported a hemicylinder 2. 3represents the weights iixed to theI hemicylinder 2, which operate inconjunction-with the other parts of the instrument to cause saidhemicylinder 2 to come to rest in such a position when the instrument isinclined that the switch-arm moves in a vertical plane. 4 5 are thebrackets fixed inside the hemicylinder 2, which support the vertical rod6.A 7 is the plumbybob pivoted at 7 to the lower end of the rod 6, 'and8 the switcharm iixed to the plumb-bob. V9 is the commutator iixed tothe rod 6 in such a position that the upper end of the switch-arm 8moves over it, and 10 is the resistance-coil which is connected' up withthe commutator in the manner hereinafter more particularly described. 11is the disk fitted in the upper end of the hemicylinder 2, which carriesthe insulating bush or blockv 12, carrying the screw 13 and disk 14,which latter is connectedby the wire 15 to the coil 10, and 16 is tdhedisk tted in the other end of the hemicylmder 2, which carries the screw17. 18 is the disk fixed inside the tube 1 above the disk 11 by means ofthe screws` 19 20, and 21 is the screw which serves as the top pivotabout'l which the hemicylinder 2 moves. 22v is an ebonite block or disk'carrying the contactrings 23 24, and 25 is thewire connecting the outercontact-rin 23 with the metal disk or plate 26 on the pivot-screw 21.other wire from the other contact-ring 24, which is located in thegroove 28 inside the tube 1, down which it passes to the bottom of thehemicylinder 2. side the tube 1 below the hemicylinder 2 by means of thescrews 30 31, and 32 is the bush or block of ebonite in which is fittedthe screw 33, which forms the pivot about which-the lower end of thehemicylinder 2 revolves, and 34 the metal plate or disk to which theWire 27 is attache l Referring now to Fi 2, the commutator 9 consists ofa number o segments of platinum 27 is the 29'is the disk fixed invI ooover the commutator "9.

pieces of ebonite or other non-conducting mabe noted that the circuit iscompleted through the complete coil 10 and that with each suceessivemetal contact the resistance is gradually cut out as the switch-arm 8travels The cbonite or other non-conducting segments 36 between themetal contacts 35 provide a break or blank alternately with each segmentof the resistance. I

What I claim as' my invention, and desire to protect by Letters Patent,is-

1. An instrument for surveyin bore-holes comprising a casin a revolu )leportion mounted therein, a p umb-bob pivota ly carried by said revolubleportion, a switch-arm carried by said plumb-bob, a commutator carried bythev revoluble portion over which the switch-arm is caused to travel asthe revoluble portion is inclinedpand a resistance- 'coil, theres'istanceecoil and commutator be-v ing so arranged that the switch-armstarts from a normal position with a maximum resistanceand as it passesover the commutator gradually varies the resistance, substantially asdescribed.

2. An instrument for surveying bore-holes comprising in combination acasing, a portion n pivoted therein, said portion being weighted uponone side, a plumb-bob carried by said` pivoted portion, a switch-armcarried by said plumb-bob, a commutatorand -a resistancecoil carried bysaid pivoted portion, said commutator consisting of a number of metalcontacts interspaced with non-comlucting material, the commutator andcoil being so connected that the switch-arm starts from a normalposition with a maximum resistance and gradually as it asses over thecommutator cuts out the resistance and provides a blank between eachsegment of the resistance, substantially as described. l

3. In an instrument for surveying borcholes in combination, an outercasing, a portion pivoted thereil'i, said portion being weighted uponone side, a plumb-bob carried by said pivoted portion, a switch-arm.carried by said plumb-bob a commutator and a resistance-coil carried bysaid. pivoted portion and arranged so that the declination of tbe plumbbob from the Vertical causes tbe switch-arm to move over the commutator,

the commutator and coil being arranged so that the switch-arm startsfrom a normal position with a maximum resistance and gradually as itpasses over the comn'iutator cuts out the resistance, each successivemetal contact being interspaced with insulating material which forms ablank or break in the circuit, substantially as described.

In witness whereof I have hereunto set my hand in the presence of twosubscribing witnesses.-

HUGH FREDERICK MARRIOTT, Witnesses:

CHAs. OvENDALE, R. OVENDALE.

